1. Field of Invention
The invention relates to a scanning device with multiple LED light sources and an application thereof, and more particularly to a scanning device having main and auxiliary LED light sources to enhance the quality of scanning a book, and a multi-function peripheral and a digital copier using the scanning device.
2. Related Art
When a conventional scanner is scanning a book, a cold cathode fluorescent lamp is provided to illuminate the book. However, two ends of a linear cold cathode fluorescent lamp have the lower brightness, so the scanned results near the ridge portion of the gutter side of the book become darker. In order to solve this problem, a curved lamp may be provided for the brightness compensation. However, the curved cold cathode fluorescent lamp still has the drawbacks including the long warm-up time, the non-uniform brightness distribution and the attenuating brightness with the elapsing of time.
With the rapid development of the light-emitting diode (LED) technology, the future LED may serve as a light source for the scanner. However, a plurality of LEDs has to be packaged on a printed circuit board, and the LED light source cannot be integrally formed into a curved shape to enhance the brightness at the end portion thereof.